Electric glass-furnace.



5.0.'ERSK1NE.

ELfECTRLC GLASS FURNACE.

APPLlcATloN FlLEn Nov. 21. i917.

Patented May 21, 1918.

JOHN O. ERSKINE, 0F STEUBENVILLE, OHIO.

ELECTRIC GLASS-FURNACE.

i Speoication of Letters Patent. Patented May 21, 1918.

Application led November 21, 1917. Serial No. 208,116.

To all whom t may concern.' 4

Be it known that I, JOHN O. ERSKINE, a citizen of the United States of America, and resident of Steubenville, county of Jefferson, and State of Ohio, have invented certain new and useful mprovements in E1ectric Glass-Furnaces, of which the following is a specification.

This invention relates broadly to electric furnaces, and it has for its object to provide a glass melting furnace or tank wherein the materials, or batch, and for maintaining the plastic condition of the glass when melted, is produced by the conversion of electrica energy.

A further object is to provide an electrically heated glass furnace in which the melting heat is generated by the relatively great resista-nce to the current offered by thel glass material, and in which, furthermore, the use of a lining of carbon, common to electric furnaces, is dispensed with.

A still further and very important object of the invention is to provide a selfcontained glass furnace or tank which may be worked continuously and which is adapted to be made in such relatively small sizes that a plurality thereof may be located in out-oftheway corners or otherwise unutilized areas of the glass plant.

With these and other objects in view, the invention resides in the features of construction. arrangement of parts and combination of elements which will hereinafter be eX- emplified. reference being had to the accom? panying drawin in which- Figure l is a side elevation of a glass furnace embodying my invention;

Fig. 2 is a central longitudinal section of the same; and- Fig. 3 is a section on line 3 3. FigQQ.

Referring to said drawings in which like designating characters distinguish like parts throughout the several views- 1 indicates the melting` chamber and 2 the Working chamber of my furnace, the Walls, tloor and top of-which are composed of suit eat employed for melting the glassable tile or other refractory material. herein shown for illustrative purposes, the

furnace is rectangular in shape, but it may electrodes, preferably composed of carbon,l

which may be located with respect to each other in any suitable arrangement. In the present preferred embodiment. two electrodesl 6 and 7 are located in the melting chamber 1 and two electrodes 8 and 9 in the Working chamber 2. Said electrodes are adjustabl'y mounted so that their positions with respect to the contents of the furnace may be adjusted as desired; and, in order" to shield the bodies thereof against deterioration due to heat generated in the furnace, each is embraced by a sleeve-like shield 10 of refractory material which depends Within the furnace to a point slightly above the normal maximum level of said contents, leaving Unshielded only a relatively short length of the end of each electrode` as shown. Instead of the separate shield 10 a coating of -a heat-resisting cement may be applied as a protectingv sheath to the body of the electrode.

Said electrodes are wired in series with the electrode 6 located in the melting chamber constituting, in the normal circuit, a positive pole and any desired one of the electrodes 7, 8 or 9, the negative pole. switches 11, 12 and,13 being located respectively, in the lines leading to the last-mentioned electrodes so that any one of the latter may be employed in the electric circuit with the electrode 6. y

yIn practice, the glass material or batch to, be melted is introduced. as through a hopper 14, into the melting chamber l and the electrodes 6 and 71in said chamber are adjusted to positions wherein their ends .c engage or sink into said material. The elec- `12 and 13 remaining open.

. ingof said material.

he melted glass flows through the port 4; to the working chamber 2 from which it may be gathered in the usual manner, as

through ports l in the side walls or other suitably located openings in the tank.

When melting has once proceeded to the point where a considerable, or working,

quantity of molten glass is contained by the working chamber, a sufiiciently high temperature to accomplish the melting of added material introduced in the meltin chamber may be maintained by diverting t e current from the electrode 7 to one of the electrodes 8 or 9 in the working end, this being accomplished by opening the switch 11 and closing either switch 12 or 13, according as it isdesired to include the electrode v8 or 9 in the circuit. condition of the glass in the working chamber is maintained when the current is directed throu h one of the last-mentioned' electrodes. urther, the temperature may to some extent be controlled, it bein apparent that a lower temperature wil result when the circuit includes electrode 9, which is more remote than electrode 8 from the electrode 6, and vice versa.

When it is desired that heat be generated in the working chamber alone, a switch 18 located in a line 19 may be closed for diverting the current into a circuit which inn cludes only the electrodes 8 and 9. In such case the secondary switches 11 and 12 are permitted to remain open while the main switch closed.

It will-be noted. that the furnace is eX- tremely simple and inexpensive in construction. Instead of the arched silica crown which is commonly em loyed in glass melting furnaces, a plain at top composed of blocks or slabs ot a moderately heat-resisting character ina be used in the im roved furnace describe as said top is su jected to relatively low temperatures as compared with those'furnacesl in which gaseous fuels are employed. lndeed, the top may be wholly omitted from the melting chamber 1 without material disadvantage, due to the fact that melting of the material is accom plished by heat directly generated in the 15 and the secondary switch 13 are As is obvious, the molten latter rather than by heat generated in juxtaposition and requiring coninement in close proximity thereto.

What is claimed is- 1. ,The method of producing molten glass, which consists in melting constituent glassproducing materials in an electric furnace by passing a current of electricity between electrodes in contact with a bed of said materials, said bed aidording the sole resistance vfor generating the heat by which its meltin is accomplished.

2. 'l e method of producing molten glass, which consists in melting constituent glassproducing materials in an electric furnace by passing an electric current through said materials between two electrodes which have their ends submerged in said materials, the constituent materials intermediate said electrodes constituting the sole circuitcompleting conductor for the passage of said current between said electrodes and aiordinv the sole resistance for generating melting eat.

3. A. continuous glass 'meltin method 4 which consists in passing `an electric current between two electrodes having their ends submerged in molten glass in an electric furnace, so that the resistance of said glass to the passage of said current generates a melting heat, and suppl ing raw glassroducin materials to sai furnace as mo ten glass is withdrawn from the latter.

4. A continuous method of melting glass in an electric furnace havin melting and working ends, which consists in introducing raw glass-materials to be treated into the melting end in contact with molten glass contained therein, and passing an electric current through said molten glass between electrodes having their ends submerged in said molten glass for {heatin the latter through resistance oered there y to. a temperature sufficient for melting said raw materials.

5. In an electric glass furnace, a melting chamber and a working chamber, a division wall separating said chambers and havin a port therein for the passage of melte glass from the melting chamber vto the working chamber, a pair of electrodes located in the melting chamber, an electrode located in the working chamber, and means for diverting an electric circuit from one of the first-mentioned electrodes through the last-mentioned.electrode, said first-mentioned electrodes being partially submerged in the material to be melted whereby said material constitutes a resi tance element 'and the last-mentioned electrode being adapted to be partially submerged in the molten glass in the working chamber.

6. In an electric glass furnace, a melting 10 circuit from one to the other of said series` v l wired electrodes` said electrodes being adapted to contact directly with the glass material which constitutes the heating resistance element.

In testimon whereof, I afix my signature 15 in presence o two subscribing witnesses.

Y JOHN O. ERSKINE.

Witnesses:

H. E. DUNLAP, -W. F. KEMER.v 

